Most funding related to diabetes now goes into its management, but new research could help predict and prevent the development of the condition and its complications.

More than a quarter of a million New Zealanders live with diabetes. Type 2 is the most common form, occurring when the body either does not produce enough insulin, or does not respond to the insulin that is present, leading to high levels of blood glucose. If not managed carefully, it can lead to a variety of complications, such as heart disease, blindness or kidney disease.

A precursor to type 2 diabetes is pre-diabetes, which occurs when the blood glucose level is higher than normal, but not as high as in diabetes itself. Much is still unknown about these conditions, such as how to more accurately predict who is at risk, prevent the transition from pre-diabetes to diabetes, and predict and prevent some of the more serious complications.

Associate Professor Rachel Page is Director of Research and Education at the School of Food and Nutrition, College of Health. She has more than 25 years’ research experience looking at the mechanisms underlying metabolic diseases such as diabetes, stroke, cardiovascular disease and metabolic syndrome. She is interested in the impact of lifestyle changes on improving quality of life, and in trying to prevent the development of metabolic diseases.

She has a special interest in diabetes, as it runs in her family. “I didn’t go into this area because of my family history, but it has made it more meaningful, and it would be lovely to make an impact,” she says. “I’ve gone at it at many different levels, right down to trying to understand the underlying mechanisms of the disease, which then helps in looking at good target areas for preventing or stopping its progression. It’s a big area to try to make an impact in.”

If we identify what the specific combinations of antioxidants are, we could promote the food extract or make a supplement to improve blood glucose levels. I think there’s a great opportunity here for us to have an impact.

ASSOCIATE PROFESSOR RACHEL PAGE

Effects of antioxidants

In a recent project, Dr Page, in collaboration with Dr Lynne Chepulis from the Waiariki Institute of Technology and Dr Hayder Al-Aubaidy from the University of Tasmania, has been examining the effects of different combinations of antioxidants from whole foods or food extracts on blood glucose levels. So far, the tests have only been carried out in healthy people, but results show substantial reduction in the postprandial blood glucose levels. The results are intriguing, given that previous studies have shown that single antioxidants in isolation do not have a significant impact on blood glucose levels in people with type 2 diabetes.

“We think it’s the combination of antioxidants in food that’s making a difference,” Dr Page says. “So, if we identify what the specific combinations of antioxidants are, we could promote the food extract or make a supplement to improve blood glucose levels. I think there’s a great opportunity here for us to have an impact. We’re quite excited, but now we need to see whether these antioxidants have a similar impact on postprandial blood glucose levels and overall glycaemic control in people with pre-diabetes.”

In another project, Dr Page is looking at ways to predict the onset of diabetic nephropathy, or diabetic kidney disease, a severe complication of type 2 diabetes and the most frequent cause of end-stage renal disease in the Western world. At present, it is not possible to predict which patients with type 2 diabetes will develop the condition; the precise molecular mechanisms involved in the disease are not fully understood and its genetic basis is not known.

“What is really interesting is that not all people with type 2 diabetes will develop the condition,” Dr Page says. “There are two thoughts. Is it that those who develop diabetic nephropathy have a specific genetic makeup and the diabetic environment somehow triggers an onset, development and progression of that complication? Or is it the other way around—that people who do not develop diabetic nephropathy have some sort of protective mechanisms in place within their genetic makeup? We still don’t really know.”

Potential biomarker

In order to learn more, Dr Page has been investigating whether a particular protein, beta-defensin-1, could be a biomarker for diabetic nephropathy—present in those who are likely to develop the condition, and absent in those who will not. Laboratory studies have shown that this could be the case, but it has not yet been conclusively shown in humans.

So far, Dr Page has tested for the presence or absence of the protein in the blood of three groups of people: those with diabetes and diabetic nephropathy, those with non-diabetic renal disease, and a group of healthy people. Some differences were seen between the groups, but further studies are planned.

Overall, Dr Page is working towards changing the focus from management of diabetes and its complications to prediction and prevention. “If we can stop the progression from pre-diabetes to diabetes, it will have a massive impact,” she says. “There is so much being spent on management, so to be able to try to stop development of type 2 diabetes and its complications would be wonderful.”